The pharmaceutical manufacturer Amgen announced on Tuesday that an experimental obesity drug helped patients lose up to 20 percent of their weight in a year. The drug, MariTide, is given by injection once a month, compared with once a week for other obesity drugs like Wegovy and Zepbound that are already on the market.

Amgen's experimental weight loss injection, MariTide, showed up to 20% weight loss in patients without diabetes and 17% in those with diabetes after a year in a phase 2 trial. Despite higher discontinuation rates compared to other drugs,

Shares in Amgen fell by double digits Tuesday on results for the company’s MariTide shot, which is viewed as a potential rival to Wegovy and Zepbound.

With Amgen’s MariTide results at the lower end of investors’ expectation of 20% to 25% weight loss, the much-anticipated readout sent the company’s shares tumbling.

Shares of Amgen Inc. ($AMGN) edged down 0.3% in premarket trading Wednesday, on course to extend a losing streak to a third consecutive session. The decline follows the release of Phase 2 study data for its investigational weight-loss drug MariTide,

The pharmaceutical company's MariTide treatment performed well in a Phase 2 study but not as well as Wall Street expected.